SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fad2e7a9a83751e0b05cf4b0500f211e91607303a4732ce8e6b084f6a4894f96' 
  AND token = 'oJPCYqSMz36HdXRqS6KzmUxvfuDf56KUwE9Icgy7c1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}